1. Field of the Invention
The present invention relates to a production control system which includes a plurality of terminals provided in production sites and a central processor connected to the terminals via a network for transmitting production control information stored in the central processor to the terminals.
2. Description of the Prior Art
For production control including production instruction management, process specification management and quality control, production instructions, for example, are conventionally prepared on the basis of a production plan with the use of a computer, and printed out in a predetermined format on paper media for preparation of production instruction sheets, which are in turn delivered to production sites.
For the process specification management, process specification sheets prepared by recording process specification information on paper media are delivered to the production sites and kept therein and, in an actual production process, preparatory operations and production operations are performed with reference to necessary process specification sheets. For the quality control, check sheets for inspective and confirmatory operations such as dimensional accuracy checks and operation checks are prepared and, in working sites, the inspective and confirmatory operations are performed with reference to the check sheets and the results thereof are recorded on the check sheets.
Where the production control is based on the production instruction sheets, the process specification sheets and the check sheets of paper media, however, it is necessary to keep these sheets in the production sites. Where process specifications are different from machine to machine, for example, management of a tremendous number of sheets is not easy. In the production sites, some operators may be unfamiliar with the management of the sheets, so that they are slow in retrieving a required process specification sheet. Therefore, an operation may be delayed, or erroneously performed on the basis of an improper process specification sheet. Further, the paper media is liable to be damaged or smudged.
In view of the foregoing, it is an object of the present invention to provide a production control system which ensures easy storage and management of information and prompt and proper retrieval of necessary information in production sites.
In accordance with the present invention to solve the aforesaid problems, there is provided a production control system, which comprises a plurality of terminals provided in production sites and a central processor connected to the terminals via a network, wherein the central processor comprises a production control information storage section which stores information on production control, and a data distributing section for retrieving production control information from the production control information storage section in response to a request from any of the terminals and transmitting the retrieved production control information to the terminal having requested the information.
In the production control system according to the present invention, the data distributing section retrieves the production control information from the production control information storage section of the central processor in response to the request from any of the terminals provided in the production sites, and transmits the retrieved production control information to the terminal having requested the information. Thus, the production control system can centrally manage the production control information on a paperless basis. Further, the necessary production control information can promptly and properly be retrieved simply by operating the terminals in the production sites.
The production control information stored in the production control information storage section may include production instruction information on production instructions and/or process specification information on process specifications and/or inspection information on inspections.
Particularly, where the production control information includes the inspection information, the data distributing section may be adapted to receive data indicative of results of an inspection carried out on the basis of the inspection information from any of the terminals, and the central processor may include an inspection result data storage section for storing the inspection result data received by the data distributing section. Thus, the inspection result data can easily be collected for centralized management thereof.
Where products to be produced with the aid of the inventive production control system are NC machine tools, it is preferred that the terminals are respectively incorporated in numerical controllers of the NC machine tools being assembled in an assembly line. With this arrangement, an assembly-line worker can display process specification information for an assigned operation on a display provided adjacent an NC machine tool and perform the operation with reference to the process specification information. Thus, the assembly-line worker can promptly obtain necessary information without loss thereby to reliably perform the assembling operation with a drastically improved working efficiency. Further, there is no need to separately install special-purpose terminals in the production sites, so that costs for system construction can be reduced.
The network may include not only a cable communication network but also a wireless communication network.